We request funding to purchase a high-resolution desktop micro- tomographic imaging device muCT40, Scanco Medical, Basserdorf, Switzerland). This new device would represent a major upgrade to our existing (CT system, which is nearly eight years old. We have used our system to non-destructively assess the morphology and microarchitecture of porous aluminum foams, human trabecular bone specimens, and a variety of excised bone and tooth specimens from different animals (whale, cow, rat, mice, monkey, zebrafish). The role of muCT is expanding rapidly in biomedical research, as it provides a non-destructive, high-resolution, full 3D evaluation of bone density and skeletal morphology. The nondestructive nature of the technique means that following evaluation by (CT, specimens can be assessed by any number of alternative techniques, including standard histologic assessment, immunohistochemistry, or biomechanical testing to determine bone strength. This new system is necessary because our current system runs at full capacity due to the relatively slow scan acquisition times for specimens at the highest resolution and, in spite of the high demand, no new users can be accommodated without compromising turnaround times for current users. The reasons for the logjam on our current system are two-fold: 1) acquisition of the highest resolution image data (required for mice) occurs up to 1000% slower than would be capable with the new system, and 2) operating efficiency has been compromised due to frequent breakdowns associated with expected wear and tear on an eight year old system. The major scientific impact of this upgrade would be multifold. First, image data with maximal spatial resolution could be acquired in a reasonable amount of time m thereby providing the best compromise between data quality and time/cost. Second, high spatial resolution combined with a choice of X-ray energy will allow scanning of small, low mineralized specimens (i.e., neonatal mouse), as well as specimens with high mineral content (i.e., fossils). Third, the increased gantry size will allow high-resolution scanning of larger specimens. These last two features will increase the overall utility of the system for a broader spectrum of investigations than can currently be achieved. Fourth, the software capability of semiautomated finite element analysis for non-destructive estimation of mechanical behavior will add a new dimension to the analysis / outcome variables that was previously unavailable. In addition, the practical impact of this upgrade would be threefold: 1) more investigators will access to the system, 2) turnaround times will decrease, and 3) the costs per specimen will decrease. In summary, acquisition of this new muCT40 system will strongly benefit both ongoing and future research endeavors since the number of NIH-funded investigators in our community who want to incorporate (CT into their research continues to grow, and since we are the only academic institution in the area with a (CT system and the expertise to perform these analyses.